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/*
* SSLv3/TLSv1 shared functions
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* The SSL 3.0 specification was drafted by Netscape in 1996,
* and became an IETF standard in 1999.
*
* http://wp.netscape.com/eng/ssl3/
* http://www.ietf.org/rfc/rfc2246.txt
* http://www.ietf.org/rfc/rfc4346.txt
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_SSL_TLS_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/debug.h"
#include "mbedtls/ssl.h"
#include "mbedtls/ssl_internal.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#include "mbedtls/oid.h"
#endif
static void ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl );
static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context const *ssl );
/* Length of the "epoch" field in the record header */
static inline size_t ssl_ep_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( 2 );
#else
((void) ssl);
#endif
return( 0 );
}
/*
* Start a timer.
* Passing millisecs = 0 cancels a running timer.
*/
static void ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs )
{
if( ssl->f_set_timer == NULL )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "set_timer to %d ms", (int) millisecs ) );
ssl->f_set_timer( ssl->p_timer, millisecs / 4, millisecs );
}
/*
* Return -1 is timer is expired, 0 if it isn't.
*/
static int ssl_check_timer( mbedtls_ssl_context *ssl )
{
if( ssl->f_get_timer == NULL )
return( 0 );
if( ssl->f_get_timer( ssl->p_timer ) == 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "timer expired" ) );
return( -1 );
}
return( 0 );
}
static void ssl_update_out_pointers( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform );
static void ssl_update_in_pointers( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform );
#define SSL_DONT_FORCE_FLUSH 0
#define SSL_FORCE_FLUSH 1
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* Forward declarations for functions related to message buffering. */
static void ssl_buffering_free( mbedtls_ssl_context *ssl );
static void ssl_buffering_free_slot( mbedtls_ssl_context *ssl,
uint8_t slot );
static void ssl_free_buffered_record( mbedtls_ssl_context *ssl );
static int ssl_load_buffered_message( mbedtls_ssl_context *ssl );
static int ssl_load_buffered_record( mbedtls_ssl_context *ssl );
static int ssl_buffer_message( mbedtls_ssl_context *ssl );
static int ssl_buffer_future_record( mbedtls_ssl_context *ssl );
static int ssl_next_record_is_in_datagram( mbedtls_ssl_context *ssl );
static size_t ssl_get_current_mtu( const mbedtls_ssl_context *ssl );
static size_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl )
{
size_t mtu = ssl_get_current_mtu( ssl );
if( mtu != 0 && mtu < MBEDTLS_SSL_OUT_BUFFER_LEN )
return( mtu );
return( MBEDTLS_SSL_OUT_BUFFER_LEN );
}
static int ssl_get_remaining_space_in_datagram( mbedtls_ssl_context const *ssl )
{
size_t const bytes_written = ssl->out_left;
size_t const mtu = ssl_get_maximum_datagram_size( ssl );
/* Double-check that the write-index hasn't gone
* past what we can transmit in a single datagram. */
if( bytes_written > mtu )
{
/* Should never happen... */
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
return( (int) ( mtu - bytes_written ) );
}
static int ssl_get_remaining_payload_in_datagram( mbedtls_ssl_context const *ssl )
{
int ret;
size_t remaining, expansion;
size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
const size_t mfl = mbedtls_ssl_get_max_frag_len( ssl );
if( max_len > mfl )
max_len = mfl;
/* By the standard (RFC 6066 Sect. 4), the MFL extension
* only limits the maximum record payload size, so in theory
* we would be allowed to pack multiple records of payload size
* MFL into a single datagram. However, this would mean that there's
* no way to explicitly communicate MTU restrictions to the peer.
*
* The following reduction of max_len makes sure that we never
* write datagrams larger than MFL + Record Expansion Overhead.
*/
if( max_len <= ssl->out_left )
return( 0 );
max_len -= ssl->out_left;
#endif
ret = ssl_get_remaining_space_in_datagram( ssl );
if( ret < 0 )
return( ret );
remaining = (size_t) ret;
ret = mbedtls_ssl_get_record_expansion( ssl );
if( ret < 0 )
return( ret );
expansion = (size_t) ret;
if( remaining <= expansion )
return( 0 );
remaining -= expansion;
if( remaining >= max_len )
remaining = max_len;
return( (int) remaining );
}
/*
* Double the retransmit timeout value, within the allowed range,
* returning -1 if the maximum value has already been reached.
*/
static int ssl_double_retransmit_timeout( mbedtls_ssl_context *ssl )
{
uint32_t new_timeout;
if( ssl->handshake->retransmit_timeout >= ssl->conf->hs_timeout_max )
return( -1 );
/* Implement the final paragraph of RFC 6347 section 4.1.1.1
* in the following way: after the initial transmission and a first
* retransmission, back off to a temporary estimated MTU of 508 bytes.
* This value is guaranteed to be deliverable (if not guaranteed to be
* delivered) of any compliant IPv4 (and IPv6) network, and should work
* on most non-IP stacks too. */
if( ssl->handshake->retransmit_timeout != ssl->conf->hs_timeout_min )
{
ssl->handshake->mtu = 508;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "mtu autoreduction to %d bytes", ssl->handshake->mtu ) );
}
new_timeout = 2 * ssl->handshake->retransmit_timeout;
/* Avoid arithmetic overflow and range overflow */
if( new_timeout < ssl->handshake->retransmit_timeout ||
new_timeout > ssl->conf->hs_timeout_max )
{
new_timeout = ssl->conf->hs_timeout_max;
}
ssl->handshake->retransmit_timeout = new_timeout;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
ssl->handshake->retransmit_timeout ) );
return( 0 );
}
static void ssl_reset_retransmit_timeout( mbedtls_ssl_context *ssl )
{
ssl->handshake->retransmit_timeout = ssl->conf->hs_timeout_min;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "update timeout value to %d millisecs",
ssl->handshake->retransmit_timeout ) );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
/*
* Convert max_fragment_length codes to length.
* RFC 6066 says:
* enum{
* 2^9(1), 2^10(2), 2^11(3), 2^12(4), (255)
* } MaxFragmentLength;
* and we add 0 -> extension unused
*/
static unsigned int ssl_mfl_code_to_length( int mfl )
{
switch( mfl )
{
case MBEDTLS_SSL_MAX_FRAG_LEN_NONE:
return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN );
case MBEDTLS_SSL_MAX_FRAG_LEN_512:
return 512;
case MBEDTLS_SSL_MAX_FRAG_LEN_1024:
return 1024;
case MBEDTLS_SSL_MAX_FRAG_LEN_2048:
return 2048;
case MBEDTLS_SSL_MAX_FRAG_LEN_4096:
return 4096;
default:
return ( MBEDTLS_TLS_EXT_ADV_CONTENT_LEN );
}
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_CLI_C)
static int ssl_session_copy( mbedtls_ssl_session *dst, const mbedtls_ssl_session *src )
{
mbedtls_ssl_session_free( dst );
memcpy( dst, src, sizeof( mbedtls_ssl_session ) );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
if( src->peer_cert != NULL )
{
int ret;
dst->peer_cert = mbedtls_calloc( 1, sizeof(mbedtls_x509_crt) );
if( dst->peer_cert == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
mbedtls_x509_crt_init( dst->peer_cert );
if( ( ret = mbedtls_x509_crt_parse_der( dst->peer_cert, src->peer_cert->raw.p,
src->peer_cert->raw.len ) ) != 0 )
{
mbedtls_free( dst->peer_cert );
dst->peer_cert = NULL;
return( ret );
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
if( src->ticket != NULL )
{
dst->ticket = mbedtls_calloc( 1, src->ticket_len );
if( dst->ticket == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
memcpy( dst->ticket, src->ticket, src->ticket_len );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
return( 0 );
}
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
int (*mbedtls_ssl_hw_record_init)( mbedtls_ssl_context *ssl,
const unsigned char *key_enc, const unsigned char *key_dec,
size_t keylen,
const unsigned char *iv_enc, const unsigned char *iv_dec,
size_t ivlen,
const unsigned char *mac_enc, const unsigned char *mac_dec,
size_t maclen ) = NULL;
int (*mbedtls_ssl_hw_record_activate)( mbedtls_ssl_context *ssl, int direction) = NULL;
int (*mbedtls_ssl_hw_record_reset)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_write)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_read)( mbedtls_ssl_context *ssl ) = NULL;
int (*mbedtls_ssl_hw_record_finish)( mbedtls_ssl_context *ssl ) = NULL;
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
/*
* Key material generation
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3)
static int ssl3_prf( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
int ret = 0;
size_t i;
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char padding[16];
unsigned char sha1sum[20];
((void)label);
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
/*
* SSLv3:
* block =
* MD5( secret + SHA1( 'A' + secret + random ) ) +
* MD5( secret + SHA1( 'BB' + secret + random ) ) +
* MD5( secret + SHA1( 'CCC' + secret + random ) ) +
* ...
*/
for( i = 0; i < dlen / 16; i++ )
{
memset( padding, (unsigned char) ('A' + i), 1 + i );
if( ( ret = mbedtls_sha1_starts_ret( &sha1 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, padding, 1 + i ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, secret, slen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_update_ret( &sha1, random, rlen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_sha1_finish_ret( &sha1, sha1sum ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_starts_ret( &md5 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_update_ret( &md5, secret, slen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_update_ret( &md5, sha1sum, 20 ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md5_finish_ret( &md5, dstbuf + i * 16 ) ) != 0 )
goto exit;
}
exit:
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
mbedtls_platform_zeroize( padding, sizeof( padding ) );
mbedtls_platform_zeroize( sha1sum, sizeof( sha1sum ) );
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
static int tls1_prf( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
size_t nb, hs;
size_t i, j, k;
const unsigned char *S1, *S2;
unsigned char tmp[128];
unsigned char h_i[20];
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t md_ctx;
int ret;
mbedtls_md_init( &md_ctx );
if( sizeof( tmp ) < 20 + strlen( label ) + rlen )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
hs = ( slen + 1 ) / 2;
S1 = secret;
S2 = secret + slen - hs;
nb = strlen( label );
memcpy( tmp + 20, label, nb );
memcpy( tmp + 20 + nb, random, rlen );
nb += rlen;
/*
* First compute P_md5(secret,label+random)[0..dlen]
*/
if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_MD5 ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, S1, hs );
mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb );
mbedtls_md_hmac_finish( &md_ctx, 4 + tmp );
for( i = 0; i < dlen; i += 16 )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, 4 + tmp, 16 );
mbedtls_md_hmac_finish( &md_ctx, 4 + tmp );
k = ( i + 16 > dlen ) ? dlen % 16 : 16;
for( j = 0; j < k; j++ )
dstbuf[i + j] = h_i[j];
}
mbedtls_md_free( &md_ctx );
/*
* XOR out with P_sha1(secret,label+random)[0..dlen]
*/
if( ( md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, S2, hs );
mbedtls_md_hmac_update( &md_ctx, tmp + 20, nb );
mbedtls_md_hmac_finish( &md_ctx, tmp );
for( i = 0; i < dlen; i += 20 )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, 20 + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, 20 );
mbedtls_md_hmac_finish( &md_ctx, tmp );
k = ( i + 20 > dlen ) ? dlen % 20 : 20;
for( j = 0; j < k; j++ )
dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] );
}
mbedtls_md_free( &md_ctx );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
mbedtls_platform_zeroize( h_i, sizeof( h_i ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1) || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
static int tls_prf_generic( mbedtls_md_type_t md_type,
const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
size_t nb;
size_t i, j, k, md_len;
unsigned char tmp[128];
unsigned char h_i[MBEDTLS_MD_MAX_SIZE];
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t md_ctx;
int ret;
mbedtls_md_init( &md_ctx );
if( ( md_info = mbedtls_md_info_from_type( md_type ) ) == NULL )
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
md_len = mbedtls_md_get_size( md_info );
if( sizeof( tmp ) < md_len + strlen( label ) + rlen )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
nb = strlen( label );
memcpy( tmp + md_len, label, nb );
memcpy( tmp + md_len + nb, random, rlen );
nb += rlen;
/*
* Compute P_<hash>(secret, label + random)[0..dlen]
*/
if ( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
return( ret );
mbedtls_md_hmac_starts( &md_ctx, secret, slen );
mbedtls_md_hmac_update( &md_ctx, tmp + md_len, nb );
mbedtls_md_hmac_finish( &md_ctx, tmp );
for( i = 0; i < dlen; i += md_len )
{
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, md_len + nb );
mbedtls_md_hmac_finish( &md_ctx, h_i );
mbedtls_md_hmac_reset ( &md_ctx );
mbedtls_md_hmac_update( &md_ctx, tmp, md_len );
mbedtls_md_hmac_finish( &md_ctx, tmp );
k = ( i + md_len > dlen ) ? dlen % md_len : md_len;
for( j = 0; j < k; j++ )
dstbuf[i + j] = h_i[j];
}
mbedtls_md_free( &md_ctx );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
mbedtls_platform_zeroize( h_i, sizeof( h_i ) );
return( 0 );
}
#if defined(MBEDTLS_SHA256_C)
static int tls_prf_sha256( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
return( tls_prf_generic( MBEDTLS_MD_SHA256, secret, slen,
label, random, rlen, dstbuf, dlen ) );
}
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
static int tls_prf_sha384( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen )
{
return( tls_prf_generic( MBEDTLS_MD_SHA384, secret, slen,
label, random, rlen, dstbuf, dlen ) );
}
#endif /* MBEDTLS_SHA512_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
static void ssl_update_checksum_start( mbedtls_ssl_context *, const unsigned char *, size_t );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_update_checksum_md5sha1( mbedtls_ssl_context *, const unsigned char *, size_t );
#endif
#if defined(MBEDTLS_SSL_PROTO_SSL3)
static void ssl_calc_verify_ssl( mbedtls_ssl_context *, unsigned char * );
static void ssl_calc_finished_ssl( mbedtls_ssl_context *, unsigned char *, int );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
static void ssl_calc_verify_tls( mbedtls_ssl_context *, unsigned char * );
static void ssl_calc_finished_tls( mbedtls_ssl_context *, unsigned char *, int );
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
static void ssl_update_checksum_sha256( mbedtls_ssl_context *, const unsigned char *, size_t );
static void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *,unsigned char * );
static void ssl_calc_finished_tls_sha256( mbedtls_ssl_context *,unsigned char *, int );
#endif
#if defined(MBEDTLS_SHA512_C)
static void ssl_update_checksum_sha384( mbedtls_ssl_context *, const unsigned char *, size_t );
static void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *, unsigned char * );
static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *, unsigned char *, int );
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
{
int ret = 0;
unsigned char tmp[64];
unsigned char keyblk[256];
unsigned char *key1;
unsigned char *key2;
unsigned char *mac_enc;
unsigned char *mac_dec;
size_t mac_key_len;
size_t iv_copy_len;
const mbedtls_cipher_info_t *cipher_info;
const mbedtls_md_info_t *md_info;
mbedtls_ssl_session *session = ssl->session_negotiate;
mbedtls_ssl_transform *transform = ssl->transform_negotiate;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive keys" ) );
cipher_info = mbedtls_cipher_info_from_type( transform->ciphersuite_info->cipher );
if( cipher_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "cipher info for %d not found",
transform->ciphersuite_info->cipher ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
md_info = mbedtls_md_info_from_type( transform->ciphersuite_info->mac );
if( md_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "mbedtls_md info for %d not found",
transform->ciphersuite_info->mac ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/*
* Set appropriate PRF function and other SSL / TLS / TLS1.2 functions
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
handshake->tls_prf = ssl3_prf;
handshake->calc_verify = ssl_calc_verify_ssl;
handshake->calc_finished = ssl_calc_finished_ssl;
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 )
{
handshake->tls_prf = tls1_prf;
handshake->calc_verify = ssl_calc_verify_tls;
handshake->calc_finished = ssl_calc_finished_tls;
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA512_C)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
transform->ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
{
handshake->tls_prf = tls_prf_sha384;
handshake->calc_verify = ssl_calc_verify_tls_sha384;
handshake->calc_finished = ssl_calc_finished_tls_sha384;
}
else
#endif
#if defined(MBEDTLS_SHA256_C)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
handshake->tls_prf = tls_prf_sha256;
handshake->calc_verify = ssl_calc_verify_tls_sha256;
handshake->calc_finished = ssl_calc_finished_tls_sha256;
}
else
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* SSLv3:
* master =
* MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) +
* MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) +
* MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) )
*
* TLSv1+:
* master = PRF( premaster, "master secret", randbytes )[0..47]
*/
if( handshake->resume == 0 )
{
MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
handshake->pmslen );
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED )
{
unsigned char session_hash[48];
size_t hash_len;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using extended master secret" ) );
ssl->handshake->calc_verify( ssl, session_hash );
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
#if defined(MBEDTLS_SHA512_C)
if( ssl->transform_negotiate->ciphersuite_info->mac ==
MBEDTLS_MD_SHA384 )
{
hash_len = 48;
}
else
#endif
hash_len = 32;
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
hash_len = 36;
MBEDTLS_SSL_DEBUG_BUF( 3, "session hash", session_hash, hash_len );
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
"extended master secret",
session_hash, hash_len,
session->master, 48 );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
}
else
#endif
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
"master secret",
handshake->randbytes, 64,
session->master, 48 );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
mbedtls_platform_zeroize( handshake->premaster,
sizeof(handshake->premaster) );
}
else
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) );
/*
* Swap the client and server random values.
*/
memcpy( tmp, handshake->randbytes, 64 );
memcpy( handshake->randbytes, tmp + 32, 32 );
memcpy( handshake->randbytes + 32, tmp, 32 );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
/*
* SSLv3:
* key block =
* MD5( master + SHA1( 'A' + master + randbytes ) ) +
* MD5( master + SHA1( 'BB' + master + randbytes ) ) +
* MD5( master + SHA1( 'CCC' + master + randbytes ) ) +
* MD5( master + SHA1( 'DDDD' + master + randbytes ) ) +
* ...
*
* TLSv1:
* key block = PRF( master, "key expansion", randbytes )
*/
ret = handshake->tls_prf( session->master, 48, "key expansion",
handshake->randbytes, 64, keyblk, 256 );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite = %s",
mbedtls_ssl_get_ciphersuite_name( session->ciphersuite ) ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "master secret", session->master, 48 );
MBEDTLS_SSL_DEBUG_BUF( 4, "random bytes", handshake->randbytes, 64 );
MBEDTLS_SSL_DEBUG_BUF( 4, "key block", keyblk, 256 );
mbedtls_platform_zeroize( handshake->randbytes,
sizeof( handshake->randbytes ) );
/*
* Determine the appropriate key, IV and MAC length.
*/
transform->keylen = cipher_info->key_bitlen / 8;
if( cipher_info->mode == MBEDTLS_MODE_GCM ||
cipher_info->mode == MBEDTLS_MODE_CCM ||
cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY )
{
size_t taglen, explicit_ivlen;
transform->maclen = 0;
mac_key_len = 0;
/* All modes haves 96-bit IVs;
* GCM and CCM has 4 implicit and 8 explicit bytes
* ChachaPoly has all 12 bytes implicit
*/
transform->ivlen = 12;
if( cipher_info->mode == MBEDTLS_MODE_CHACHAPOLY )
transform->fixed_ivlen = 12;
else
transform->fixed_ivlen = 4;
/* All modes have 128-bit tags, except CCM_8 (ciphersuite flag) */
taglen = transform->ciphersuite_info->flags &
MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16;
/* Minimum length of encrypted record */
explicit_ivlen = transform->ivlen - transform->fixed_ivlen;
transform->minlen = explicit_ivlen + taglen;
}
else
{
/* Initialize HMAC contexts */
if( ( ret = mbedtls_md_setup( &transform->md_ctx_enc, md_info, 1 ) ) != 0 ||
( ret = mbedtls_md_setup( &transform->md_ctx_dec, md_info, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret );
return( ret );
}
/* Get MAC length */
mac_key_len = mbedtls_md_get_size( md_info );
transform->maclen = mac_key_len;
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
/*
* If HMAC is to be truncated, we shall keep the leftmost bytes,
* (rfc 6066 page 13 or rfc 2104 section 4),
* so we only need to adjust the length here.
*/
if( session->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED )
{
transform->maclen = MBEDTLS_SSL_TRUNCATED_HMAC_LEN;
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC_COMPAT)
/* Fall back to old, non-compliant version of the truncated
* HMAC implementation which also truncates the key
* (Mbed TLS versions from 1.3 to 2.6.0) */
mac_key_len = transform->maclen;
#endif
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
/* IV length */
transform->ivlen = cipher_info->iv_size;
/* Minimum length */
if( cipher_info->mode == MBEDTLS_MODE_STREAM )
transform->minlen = transform->maclen;
else
{
/*
* GenericBlockCipher:
* 1. if EtM is in use: one block plus MAC
* otherwise: * first multiple of blocklen greater than maclen
* 2. IV except for SSL3 and TLS 1.0
*/
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( session->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
{
transform->minlen = transform->maclen
+ cipher_info->block_size;
}
else
#endif
{
transform->minlen = transform->maclen
+ cipher_info->block_size
- transform->maclen % cipher_info->block_size;
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_1 )
; /* No need to adjust minlen */
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_2 ||
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
{
transform->minlen += transform->ivlen;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d",
transform->keylen, transform->minlen, transform->ivlen,
transform->maclen ) );
/*
* Finally setup the cipher contexts, IVs and MAC secrets.
*/
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
{
key1 = keyblk + mac_key_len * 2;
key2 = keyblk + mac_key_len * 2 + transform->keylen;
mac_enc = keyblk;
mac_dec = keyblk + mac_key_len;
/*
* This is not used in TLS v1.1.
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
memcpy( transform->iv_enc, key2 + transform->keylen, iv_copy_len );
memcpy( transform->iv_dec, key2 + transform->keylen + iv_copy_len,
iv_copy_len );
}
else
#endif /* MBEDTLS_SSL_CLI_C */
#if defined(MBEDTLS_SSL_SRV_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER )
{
key1 = keyblk + mac_key_len * 2 + transform->keylen;
key2 = keyblk + mac_key_len * 2;
mac_enc = keyblk + mac_key_len;
mac_dec = keyblk;
/*
* This is not used in TLS v1.1.
*/
iv_copy_len = ( transform->fixed_ivlen ) ?
transform->fixed_ivlen : transform->ivlen;
memcpy( transform->iv_dec, key1 + transform->keylen, iv_copy_len );
memcpy( transform->iv_enc, key1 + transform->keylen + iv_copy_len,
iv_copy_len );
}
else
#endif /* MBEDTLS_SSL_SRV_C */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( mac_key_len > sizeof transform->mac_enc )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
memcpy( transform->mac_enc, mac_enc, mac_key_len );
memcpy( transform->mac_dec, mac_dec, mac_key_len );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
{
/* For HMAC-based ciphersuites, initialize the HMAC transforms.
For AEAD-based ciphersuites, there is nothing to do here. */
if( mac_key_len != 0 )
{
mbedtls_md_hmac_starts( &transform->md_ctx_enc, mac_enc, mac_key_len );
mbedtls_md_hmac_starts( &transform->md_ctx_dec, mac_dec, mac_key_len );
}
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_init != NULL )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) );
if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, transform->keylen,
transform->iv_enc, transform->iv_dec,
iv_copy_len,
mac_enc, mac_dec,
mac_key_len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_init", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
#if defined(MBEDTLS_SSL_EXPORT_KEYS)
if( ssl->conf->f_export_keys != NULL )
{
ssl->conf->f_export_keys( ssl->conf->p_export_keys,
session->master, keyblk,
mac_key_len, transform->keylen,
iv_copy_len );
}
#endif
if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_enc,
cipher_info ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setup( &transform->cipher_ctx_dec,
cipher_info ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setup", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_enc, key1,
cipher_info->key_bitlen,
MBEDTLS_ENCRYPT ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_setkey( &transform->cipher_ctx_dec, key2,
cipher_info->key_bitlen,
MBEDTLS_DECRYPT ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_setkey", ret );
return( ret );
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( cipher_info->mode == MBEDTLS_MODE_CBC )
{
if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_enc,
MBEDTLS_PADDING_NONE ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret );
return( ret );
}
if( ( ret = mbedtls_cipher_set_padding_mode( &transform->cipher_ctx_dec,
MBEDTLS_PADDING_NONE ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_set_padding_mode", ret );
return( ret );
}
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
mbedtls_platform_zeroize( keyblk, sizeof( keyblk ) );
#if defined(MBEDTLS_ZLIB_SUPPORT)
// Initialize compression
//
if( session->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
if( ssl->compress_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Allocating compression buffer" ) );
ssl->compress_buf = mbedtls_calloc( 1, MBEDTLS_SSL_COMPRESS_BUFFER_LEN );
if( ssl->compress_buf == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc(%d bytes) failed",
MBEDTLS_SSL_COMPRESS_BUFFER_LEN ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Initializing zlib states" ) );
memset( &transform->ctx_deflate, 0, sizeof( transform->ctx_deflate ) );
memset( &transform->ctx_inflate, 0, sizeof( transform->ctx_inflate ) );
if( deflateInit( &transform->ctx_deflate,
Z_DEFAULT_COMPRESSION ) != Z_OK ||
inflateInit( &transform->ctx_inflate ) != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Failed to initialize compression" ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
}
#endif /* MBEDTLS_ZLIB_SUPPORT */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= derive keys" ) );
return( 0 );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
void ssl_calc_verify_ssl( mbedtls_ssl_context *ssl, unsigned char hash[36] )
{
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
unsigned char pad_1[48];
unsigned char pad_2[48];
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify ssl" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
memset( pad_1, 0x36, 48 );
memset( pad_2, 0x5C, 48 );
mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 );
mbedtls_md5_update_ret( &md5, pad_1, 48 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_md5_starts_ret( &md5 );
mbedtls_md5_update_ret( &md5, ssl->session_negotiate->master, 48 );
mbedtls_md5_update_ret( &md5, pad_2, 48 );
mbedtls_md5_update_ret( &md5, hash, 16 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 );
mbedtls_sha1_update_ret( &sha1, pad_1, 40 );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
mbedtls_sha1_starts_ret( &sha1 );
mbedtls_sha1_update_ret( &sha1, ssl->session_negotiate->master, 48 );
mbedtls_sha1_update_ret( &sha1, pad_2, 40 );
mbedtls_sha1_update_ret( &sha1, hash + 16, 20 );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
return;
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
void ssl_calc_verify_tls( mbedtls_ssl_context *ssl, unsigned char hash[36] )
{
mbedtls_md5_context md5;
mbedtls_sha1_context sha1;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify tls" ) );
mbedtls_md5_init( &md5 );
mbedtls_sha1_init( &sha1 );
mbedtls_md5_clone( &md5, &ssl->handshake->fin_md5 );
mbedtls_sha1_clone( &sha1, &ssl->handshake->fin_sha1 );
mbedtls_md5_finish_ret( &md5, hash );
mbedtls_sha1_finish_ret( &sha1, hash + 16 );
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_md5_free( &md5 );
mbedtls_sha1_free( &sha1 );
return;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
void ssl_calc_verify_tls_sha256( mbedtls_ssl_context *ssl, unsigned char hash[32] )
{
mbedtls_sha256_context sha256;
mbedtls_sha256_init( &sha256 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha256" ) );
mbedtls_sha256_clone( &sha256, &ssl->handshake->fin_sha256 );
mbedtls_sha256_finish_ret( &sha256, hash );
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 32 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_sha256_free( &sha256 );
return;
}
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
void ssl_calc_verify_tls_sha384( mbedtls_ssl_context *ssl, unsigned char hash[48] )
{
mbedtls_sha512_context sha512;
mbedtls_sha512_init( &sha512 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> calc verify sha384" ) );
mbedtls_sha512_clone( &sha512, &ssl->handshake->fin_sha512 );
mbedtls_sha512_finish_ret( &sha512, hash );
MBEDTLS_SSL_DEBUG_BUF( 3, "calculated verify result", hash, 48 );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= calc verify" ) );
mbedtls_sha512_free( &sha512 );
return;
}
#endif /* MBEDTLS_SHA512_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex )
{
unsigned char *p = ssl->handshake->premaster;
unsigned char *end = p + sizeof( ssl->handshake->premaster );
const unsigned char *psk = ssl->conf->psk;
size_t psk_len = ssl->conf->psk_len;
/* If the psk callback was called, use its result */
if( ssl->handshake->psk != NULL )
{
psk = ssl->handshake->psk;
psk_len = ssl->handshake->psk_len;
}
/*
* PMS = struct {
* opaque other_secret<0..2^16-1>;
* opaque psk<0..2^16-1>;
* };
* with "other_secret" depending on the particular key exchange
*/
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_PSK )
{
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*(p++) = (unsigned char)( psk_len >> 8 );
*(p++) = (unsigned char)( psk_len );
if( end < p || (size_t)( end - p ) < psk_len )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
memset( p, 0, psk_len );
p += psk_len;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
/*
* other_secret already set by the ClientKeyExchange message,
* and is 48 bytes long
*/
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*p++ = 0;
*p++ = 48;
p += 48;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
int ret;
size_t len;
/* Write length only when we know the actual value */
if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
p + 2, end - ( p + 2 ), &len,
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
return( ret );
}
*(p++) = (unsigned char)( len >> 8 );
*(p++) = (unsigned char)( len );
p += len;
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
if( key_ex == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
int ret;
size_t zlen;
if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &zlen,
p + 2, end - ( p + 2 ),
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
return( ret );
}
*(p++) = (unsigned char)( zlen >> 8 );
*(p++) = (unsigned char)( zlen );
p += zlen;
MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* opaque psk<0..2^16-1>; */
if( end - p < 2 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
*(p++) = (unsigned char)( psk_len >> 8 );
*(p++) = (unsigned char)( psk_len );
if( end < p || (size_t)( end - p ) < psk_len )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
memcpy( p, psk, psk_len );
p += psk_len;
ssl->handshake->pmslen = p - ssl->handshake->premaster;
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/*
* SSLv3.0 MAC functions
*/
#define SSL_MAC_MAX_BYTES 20 /* MD-5 or SHA-1 */
static void ssl_mac( mbedtls_md_context_t *md_ctx,
const unsigned char *secret,
const unsigned char *buf, size_t len,
const unsigned char *ctr, int type,
unsigned char out[SSL_MAC_MAX_BYTES] )
{
unsigned char header[11];
unsigned char padding[48];
int padlen;
int md_size = mbedtls_md_get_size( md_ctx->md_info );
int md_type = mbedtls_md_get_type( md_ctx->md_info );
/* Only MD5 and SHA-1 supported */
if( md_type == MBEDTLS_MD_MD5 )
padlen = 48;
else
padlen = 40;
memcpy( header, ctr, 8 );
header[ 8] = (unsigned char) type;
header[ 9] = (unsigned char)( len >> 8 );
header[10] = (unsigned char)( len );
memset( padding, 0x36, padlen );
mbedtls_md_starts( md_ctx );
mbedtls_md_update( md_ctx, secret, md_size );
mbedtls_md_update( md_ctx, padding, padlen );
mbedtls_md_update( md_ctx, header, 11 );
mbedtls_md_update( md_ctx, buf, len );
mbedtls_md_finish( md_ctx, out );
memset( padding, 0x5C, padlen );
mbedtls_md_starts( md_ctx );
mbedtls_md_update( md_ctx, secret, md_size );
mbedtls_md_update( md_ctx, padding, padlen );
mbedtls_md_update( md_ctx, out, md_size );
mbedtls_md_finish( md_ctx, out );
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
( defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C)) )
#define SSL_SOME_MODES_USE_MAC
#endif
/* The function below is only used in the Lucky 13 counter-measure in
* ssl_decrypt_buf(). These are the defines that guard the call site. */
#if defined(SSL_SOME_MODES_USE_MAC) && \
( defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2) )
/* This function makes sure every byte in the memory region is accessed
* (in ascending addresses order) */
static void ssl_read_memory( unsigned char *p, size_t len )
{
unsigned char acc = 0;
volatile unsigned char force;
for( ; len != 0; p++, len-- )
acc ^= *p;
force = acc;
(void) force;
}
#endif /* SSL_SOME_MODES_USE_MAC && ( TLS1 || TLS1_1 || TLS1_2 ) */
/*
* Encryption/decryption functions
*/
static int ssl_encrypt_buf( mbedtls_ssl_context *ssl )
{
mbedtls_cipher_mode_t mode;
int auth_done = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) );
if( ssl->session_out == NULL || ssl->transform_out == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
mode = mbedtls_cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc );
MBEDTLS_SSL_DEBUG_BUF( 4, "before encrypt: output payload",
ssl->out_msg, ssl->out_msglen );
/*
* Add MAC before if needed
*/
#if defined(SSL_SOME_MODES_USE_MAC)
if( mode == MBEDTLS_MODE_STREAM ||
( mode == MBEDTLS_MODE_CBC
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
&& ssl->session_out->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED
#endif
) )
{
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
unsigned char mac[SSL_MAC_MAX_BYTES];
ssl_mac( &ssl->transform_out->md_ctx_enc,
ssl->transform_out->mac_enc,
ssl->out_msg, ssl->out_msglen,
ssl->out_ctr, ssl->out_msgtype,
mac );
memcpy( ssl->out_msg + ssl->out_msglen, mac, ssl->transform_out->maclen );
}
else
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 )
{
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_ctr, 8 );
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_hdr, 3 );
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_len, 2 );
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc,
ssl->out_msg, ssl->out_msglen );
mbedtls_md_hmac_finish( &ssl->transform_out->md_ctx_enc, mac );
mbedtls_md_hmac_reset( &ssl->transform_out->md_ctx_enc );
memcpy( ssl->out_msg + ssl->out_msglen, mac, ssl->transform_out->maclen );
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "computed mac",
ssl->out_msg + ssl->out_msglen,
ssl->transform_out->maclen );
ssl->out_msglen += ssl->transform_out->maclen;
auth_done++;
}
#endif /* AEAD not the only option */
/*
* Encrypt
*/
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
if( mode == MBEDTLS_MODE_STREAM )
{
int ret;
size_t olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of padding",
ssl->out_msglen, 0 ) );
if( ( ret = mbedtls_cipher_crypt( &ssl->transform_out->cipher_ctx_enc,
ssl->transform_out->iv_enc,
ssl->transform_out->ivlen,
ssl->out_msg, ssl->out_msglen,
ssl->out_msg, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( ssl->out_msglen != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
#if defined(MBEDTLS_GCM_C) || \
defined(MBEDTLS_CCM_C) || \
defined(MBEDTLS_CHACHAPOLY_C)
if( mode == MBEDTLS_MODE_GCM ||
mode == MBEDTLS_MODE_CCM ||
mode == MBEDTLS_MODE_CHACHAPOLY )
{
int ret;
size_t enc_msglen, olen;
unsigned char *enc_msg;
unsigned char add_data[13];
unsigned char iv[12];
mbedtls_ssl_transform *transform = ssl->transform_out;
unsigned char taglen = transform->ciphersuite_info->flags &
MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16;
size_t explicit_ivlen = transform->ivlen - transform->fixed_ivlen;
/*
* Prepare additional authenticated data
*/
memcpy( add_data, ssl->out_ctr, 8 );
add_data[8] = ssl->out_msgtype;
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, add_data + 9 );
add_data[11] = ( ssl->out_msglen >> 8 ) & 0xFF;
add_data[12] = ssl->out_msglen & 0xFF;
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data for AEAD", add_data, 13 );
/*
* Generate IV
*/
if( transform->ivlen == 12 && transform->fixed_ivlen == 4 )
{
/* GCM and CCM: fixed || explicit (=seqnum) */
memcpy( iv, transform->iv_enc, transform->fixed_ivlen );
memcpy( iv + transform->fixed_ivlen, ssl->out_ctr, 8 );
memcpy( ssl->out_iv, ssl->out_ctr, 8 );
}
else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 )
{
/* ChachaPoly: fixed XOR sequence number */
unsigned char i;
memcpy( iv, transform->iv_enc, transform->fixed_ivlen );
for( i = 0; i < 8; i++ )
iv[i+4] ^= ssl->out_ctr[i];
}
else
{
/* Reminder if we ever add an AEAD mode with a different size */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (internal)",
iv, transform->ivlen );
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used (transmitted)",
ssl->out_iv, explicit_ivlen );
/*
* Fix message length with added IV
*/
enc_msg = ssl->out_msg;
enc_msglen = ssl->out_msglen;
ssl->out_msglen += explicit_ivlen;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including 0 bytes of padding",
ssl->out_msglen ) );
/*
* Encrypt and authenticate
*/
if( ( ret = mbedtls_cipher_auth_encrypt( &transform->cipher_ctx_enc,
iv, transform->ivlen,
add_data, 13,
enc_msg, enc_msglen,
enc_msg, &olen,
enc_msg + enc_msglen, taglen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_encrypt", ret );
return( ret );
}
if( olen != enc_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->out_msglen += taglen;
auth_done++;
MBEDTLS_SSL_DEBUG_BUF( 4, "after encrypt: tag", enc_msg + enc_msglen, taglen );
}
else
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */
#if defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) )
if( mode == MBEDTLS_MODE_CBC )
{
int ret;
unsigned char *enc_msg;
size_t enc_msglen, padlen, olen = 0, i;
padlen = ssl->transform_out->ivlen - ( ssl->out_msglen + 1 ) %
ssl->transform_out->ivlen;
if( padlen == ssl->transform_out->ivlen )
padlen = 0;
for( i = 0; i <= padlen; i++ )
ssl->out_msg[ssl->out_msglen + i] = (unsigned char) padlen;
ssl->out_msglen += padlen + 1;
enc_msglen = ssl->out_msglen;
enc_msg = ssl->out_msg;
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
/*
* Prepend per-record IV for block cipher in TLS v1.1 and up as per
* Method 1 (6.2.3.2. in RFC4346 and RFC5246)
*/
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
/*
* Generate IV
*/
ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->transform_out->iv_enc,
ssl->transform_out->ivlen );
if( ret != 0 )
return( ret );
memcpy( ssl->out_iv, ssl->transform_out->iv_enc,
ssl->transform_out->ivlen );
/*
* Fix pointer positions and message length with added IV
*/
enc_msg = ssl->out_msg;
enc_msglen = ssl->out_msglen;
ssl->out_msglen += ssl->transform_out->ivlen;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, "
"including %d bytes of IV and %d bytes of padding",
ssl->out_msglen, ssl->transform_out->ivlen,
padlen + 1 ) );
if( ( ret = mbedtls_cipher_crypt( &ssl->transform_out->cipher_ctx_enc,
ssl->transform_out->iv_enc,
ssl->transform_out->ivlen,
enc_msg, enc_msglen,
enc_msg, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( enc_msglen != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
{
/*
* Save IV in SSL3 and TLS1
*/
memcpy( ssl->transform_out->iv_enc,
ssl->transform_out->cipher_ctx_enc.iv,
ssl->transform_out->ivlen );
}
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( auth_done == 0 )
{
unsigned char mac[MBEDTLS_SSL_MAC_ADD];
/*
* MAC(MAC_write_key, seq_num +
* TLSCipherText.type +
* TLSCipherText.version +
* length_of( (IV +) ENC(...) ) +
* IV + // except for TLS 1.0
* ENC(content + padding + padding_length));
*/
unsigned char pseudo_hdr[13];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
memcpy( pseudo_hdr + 0, ssl->out_ctr, 8 );
memcpy( pseudo_hdr + 8, ssl->out_hdr, 3 );
pseudo_hdr[11] = (unsigned char)( ( ssl->out_msglen >> 8 ) & 0xFF );
pseudo_hdr[12] = (unsigned char)( ( ssl->out_msglen ) & 0xFF );
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 );
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc, pseudo_hdr, 13 );
mbedtls_md_hmac_update( &ssl->transform_out->md_ctx_enc,
ssl->out_iv, ssl->out_msglen );
mbedtls_md_hmac_finish( &ssl->transform_out->md_ctx_enc, mac );
mbedtls_md_hmac_reset( &ssl->transform_out->md_ctx_enc );
memcpy( ssl->out_iv + ssl->out_msglen, mac,
ssl->transform_out->maclen );
ssl->out_msglen += ssl->transform_out->maclen;
auth_done++;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
}
else
#endif /* MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* Make extra sure authentication was performed, exactly once */
if( auth_done != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) );
return( 0 );
}
static int ssl_decrypt_buf( mbedtls_ssl_context *ssl )
{
mbedtls_cipher_mode_t mode;
int auth_done = 0;
#if defined(SSL_SOME_MODES_USE_MAC)
size_t padlen = 0, correct = 1;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) );
if( ssl->session_in == NULL || ssl->transform_in == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
mode = mbedtls_cipher_get_cipher_mode( &ssl->transform_in->cipher_ctx_dec );
if( ssl->in_msglen < ssl->transform_in->minlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "in_msglen (%d) < minlen (%d)",
ssl->in_msglen, ssl->transform_in->minlen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
if( mode == MBEDTLS_MODE_STREAM )
{
int ret;
size_t olen = 0;
padlen = 0;
if( ( ret = mbedtls_cipher_crypt( &ssl->transform_in->cipher_ctx_dec,
ssl->transform_in->iv_dec,
ssl->transform_in->ivlen,
ssl->in_msg, ssl->in_msglen,
ssl->in_msg, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( ssl->in_msglen != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_ARC4_C || MBEDTLS_CIPHER_NULL_CIPHER */
#if defined(MBEDTLS_GCM_C) || \
defined(MBEDTLS_CCM_C) || \
defined(MBEDTLS_CHACHAPOLY_C)
if( mode == MBEDTLS_MODE_GCM ||
mode == MBEDTLS_MODE_CCM ||
mode == MBEDTLS_MODE_CHACHAPOLY )
{
int ret;
size_t dec_msglen, olen;
unsigned char *dec_msg;
unsigned char *dec_msg_result;
unsigned char add_data[13];
unsigned char iv[12];
mbedtls_ssl_transform *transform = ssl->transform_in;
unsigned char taglen = transform->ciphersuite_info->flags &
MBEDTLS_CIPHERSUITE_SHORT_TAG ? 8 : 16;
size_t explicit_iv_len = transform->ivlen - transform->fixed_ivlen;
/*
* Compute and update sizes
*/
if( ssl->in_msglen < explicit_iv_len + taglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < explicit_iv_len (%d) "
"+ taglen (%d)", ssl->in_msglen,
explicit_iv_len, taglen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
dec_msglen = ssl->in_msglen - explicit_iv_len - taglen;
dec_msg = ssl->in_msg;
dec_msg_result = ssl->in_msg;
ssl->in_msglen = dec_msglen;
/*
* Prepare additional authenticated data
*/
memcpy( add_data, ssl->in_ctr, 8 );
add_data[8] = ssl->in_msgtype;
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, add_data + 9 );
add_data[11] = ( ssl->in_msglen >> 8 ) & 0xFF;
add_data[12] = ssl->in_msglen & 0xFF;
MBEDTLS_SSL_DEBUG_BUF( 4, "additional data for AEAD", add_data, 13 );
/*
* Prepare IV
*/
if( transform->ivlen == 12 && transform->fixed_ivlen == 4 )
{
/* GCM and CCM: fixed || explicit (transmitted) */
memcpy( iv, transform->iv_dec, transform->fixed_ivlen );
memcpy( iv + transform->fixed_ivlen, ssl->in_iv, 8 );
}
else if( transform->ivlen == 12 && transform->fixed_ivlen == 12 )
{
/* ChachaPoly: fixed XOR sequence number */
unsigned char i;
memcpy( iv, transform->iv_dec, transform->fixed_ivlen );
for( i = 0; i < 8; i++ )
iv[i+4] ^= ssl->in_ctr[i];
}
else
{
/* Reminder if we ever add an AEAD mode with a different size */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "IV used", iv, transform->ivlen );
MBEDTLS_SSL_DEBUG_BUF( 4, "TAG used", dec_msg + dec_msglen, taglen );
/*
* Decrypt and authenticate
*/
if( ( ret = mbedtls_cipher_auth_decrypt( &ssl->transform_in->cipher_ctx_dec,
iv, transform->ivlen,
add_data, 13,
dec_msg, dec_msglen,
dec_msg_result, &olen,
dec_msg + dec_msglen, taglen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_auth_decrypt", ret );
if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED )
return( MBEDTLS_ERR_SSL_INVALID_MAC );
return( ret );
}
auth_done++;
if( olen != dec_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_GCM_C || MBEDTLS_CCM_C */
#if defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || defined(MBEDTLS_CAMELLIA_C) || defined(MBEDTLS_ARIA_C) )
if( mode == MBEDTLS_MODE_CBC )
{
/*
* Decrypt and check the padding
*/
int ret;
unsigned char *dec_msg;
unsigned char *dec_msg_result;
size_t dec_msglen;
size_t minlen = 0;
size_t olen = 0;
/*
* Check immediate ciphertext sanity
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
minlen += ssl->transform_in->ivlen;
#endif
if( ssl->in_msglen < minlen + ssl->transform_in->ivlen ||
ssl->in_msglen < minlen + ssl->transform_in->maclen + 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < max( ivlen(%d), maclen (%d) "
"+ 1 ) ( + expl IV )", ssl->in_msglen,
ssl->transform_in->ivlen,
ssl->transform_in->maclen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
dec_msglen = ssl->in_msglen;
dec_msg = ssl->in_msg;
dec_msg_result = ssl->in_msg;
/*
* Authenticate before decrypt if enabled
*/
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
if( ssl->session_in->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
{
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
unsigned char pseudo_hdr[13];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "using encrypt then mac" ) );
dec_msglen -= ssl->transform_in->maclen;
ssl->in_msglen -= ssl->transform_in->maclen;
memcpy( pseudo_hdr + 0, ssl->in_ctr, 8 );
memcpy( pseudo_hdr + 8, ssl->in_hdr, 3 );
pseudo_hdr[11] = (unsigned char)( ( ssl->in_msglen >> 8 ) & 0xFF );
pseudo_hdr[12] = (unsigned char)( ( ssl->in_msglen ) & 0xFF );
MBEDTLS_SSL_DEBUG_BUF( 4, "MAC'd meta-data", pseudo_hdr, 13 );
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, pseudo_hdr, 13 );
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec,
ssl->in_iv, ssl->in_msglen );
mbedtls_md_hmac_finish( &ssl->transform_in->md_ctx_dec, mac_expect );
mbedtls_md_hmac_reset( &ssl->transform_in->md_ctx_dec );
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", ssl->in_iv + ssl->in_msglen,
ssl->transform_in->maclen );
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect,
ssl->transform_in->maclen );
if( mbedtls_ssl_safer_memcmp( ssl->in_iv + ssl->in_msglen, mac_expect,
ssl->transform_in->maclen ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
auth_done++;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
/*
* Check length sanity
*/
if( ssl->in_msglen % ssl->transform_in->ivlen != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0",
ssl->in_msglen, ssl->transform_in->ivlen ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
#if defined(MBEDTLS_SSL_PROTO_TLS1_1) || defined(MBEDTLS_SSL_PROTO_TLS1_2)
/*
* Initialize for prepended IV for block cipher in TLS v1.1 and up
*/
if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_2 )
{
unsigned char i;
dec_msglen -= ssl->transform_in->ivlen;
ssl->in_msglen -= ssl->transform_in->ivlen;
for( i = 0; i < ssl->transform_in->ivlen; i++ )
ssl->transform_in->iv_dec[i] = ssl->in_iv[i];
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 || MBEDTLS_SSL_PROTO_TLS1_2 */
if( ( ret = mbedtls_cipher_crypt( &ssl->transform_in->cipher_ctx_dec,
ssl->transform_in->iv_dec,
ssl->transform_in->ivlen,
dec_msg, dec_msglen,
dec_msg_result, &olen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_cipher_crypt", ret );
return( ret );
}
if( dec_msglen != olen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1)
if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 )
{
/*
* Save IV in SSL3 and TLS1
*/
memcpy( ssl->transform_in->iv_dec,
ssl->transform_in->cipher_ctx_dec.iv,
ssl->transform_in->ivlen );
}
#endif
padlen = 1 + ssl->in_msg[ssl->in_msglen - 1];
if( ssl->in_msglen < ssl->transform_in->maclen + padlen &&
auth_done == 0 )
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)",
ssl->in_msglen, ssl->transform_in->maclen, padlen ) );
#endif
padlen = 0;
correct = 0;
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
if( padlen > ssl->transform_in->ivlen )
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, "
"should be no more than %d",
padlen, ssl->transform_in->ivlen ) );
#endif
correct = 0;
}
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
{
/*
* TLSv1+: always check the padding up to the first failure
* and fake check up to 256 bytes of padding
*/
size_t pad_count = 0, real_count = 1;
size_t padding_idx = ssl->in_msglen - padlen;
size_t i;
/*
* Padding is guaranteed to be incorrect if:
* 1. padlen > ssl->in_msglen
*
* 2. padding_idx > MBEDTLS_SSL_IN_CONTENT_LEN +
* ssl->transform_in->maclen
*
* In both cases we reset padding_idx to a safe value (0) to
* prevent out-of-buffer reads.
*/
correct &= ( padlen <= ssl->in_msglen );
correct &= ( padding_idx <= MBEDTLS_SSL_IN_CONTENT_LEN +
ssl->transform_in->maclen );
padding_idx *= correct;
for( i = 0; i < 256; i++ )
{
real_count &= ( i < padlen );
pad_count += real_count *
( ssl->in_msg[padding_idx + i] == padlen - 1 );
}
correct &= ( pad_count == padlen ); /* Only 1 on correct padding */
#if defined(MBEDTLS_SSL_DEBUG_ALL)
if( padlen > 0 && correct == 0 )
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) );
#endif
padlen &= correct * 0x1FF;
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->in_msglen -= padlen;
}
else
#endif /* MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_CAMELLIA_C || MBEDTLS_ARIA_C ) */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_BUF( 4, "raw buffer after decryption",
ssl->in_msg, ssl->in_msglen );
#endif
/*
* Authenticate if not done yet.
* Compute the MAC regardless of the padding result (RFC4346, CBCTIME).
*/
#if defined(SSL_SOME_MODES_USE_MAC)
if( auth_done == 0 )
{
unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
ssl->in_msglen -= ssl->transform_in->maclen;
ssl->in_len[0] = (unsigned char)( ssl->in_msglen >> 8 );
ssl->in_len[1] = (unsigned char)( ssl->in_msglen );
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
ssl_mac( &ssl->transform_in->md_ctx_dec,
ssl->transform_in->mac_dec,
ssl->in_msg, ssl->in_msglen,
ssl->in_ctr, ssl->in_msgtype,
mac_expect );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver > MBEDTLS_SSL_MINOR_VERSION_0 )
{
/*
* Process MAC and always update for padlen afterwards to make
* total time independent of padlen.
*
* Known timing attacks:
* - Lucky Thirteen (http://www.isg.rhul.ac.uk/tls/TLStiming.pdf)
*
* To compensate for different timings for the MAC calculation
* depending on how much padding was removed (which is determined
* by padlen), process extra_run more blocks through the hash
* function.
*
* The formula in the paper is
* extra_run = ceil( (L1-55) / 64 ) - ceil( (L2-55) / 64 )
* where L1 is the size of the header plus the decrypted message
* plus CBC padding and L2 is the size of the header plus the
* decrypted message. This is for an underlying hash function
* with 64-byte blocks.
* We use ( (Lx+8) / 64 ) to handle 'negative Lx' values
* correctly. We round down instead of up, so -56 is the correct
* value for our calculations instead of -55.
*
* Repeat the formula rather than defining a block_size variable.
* This avoids requiring division by a variable at runtime
* (which would be marginally less efficient and would require
* linking an extra division function in some builds).
*/
size_t j, extra_run = 0;
/*
* The next two sizes are the minimum and maximum values of
* in_msglen over all padlen values.
*
* They're independent of padlen, since we previously did
* in_msglen -= padlen.
*
* Note that max_len + maclen is never more than the buffer
* length, as we previously did in_msglen -= maclen too.
*/
const size_t max_len = ssl->in_msglen + padlen;
const size_t min_len = ( max_len > 256 ) ? max_len - 256 : 0;
switch( ssl->transform_in->ciphersuite_info->mac )
{
#if defined(MBEDTLS_MD5_C) || defined(MBEDTLS_SHA1_C) || \
defined(MBEDTLS_SHA256_C)
case MBEDTLS_MD_MD5:
case MBEDTLS_MD_SHA1:
case MBEDTLS_MD_SHA256:
/* 8 bytes of message size, 64-byte compression blocks */
extra_run = ( 13 + ssl->in_msglen + padlen + 8 ) / 64 -
( 13 + ssl->in_msglen + 8 ) / 64;
break;
#endif
#if defined(MBEDTLS_SHA512_C)
case MBEDTLS_MD_SHA384:
/* 16 bytes of message size, 128-byte compression blocks */
extra_run = ( 13 + ssl->in_msglen + padlen + 16 ) / 128 -
( 13 + ssl->in_msglen + 16 ) / 128;
break;
#endif
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
extra_run &= correct * 0xFF;
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_ctr, 8 );
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_hdr, 3 );
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_len, 2 );
mbedtls_md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_msg,
ssl->in_msglen );
/* Make sure we access everything even when padlen > 0. This
* makes the synchronisation requirements for just-in-time
* Prime+Probe attacks much tighter and hopefully impractical. */
ssl_read_memory( ssl->in_msg + ssl->in_msglen, padlen );
mbedtls_md_hmac_finish( &ssl->transform_in->md_ctx_dec, mac_expect );
/* Call mbedtls_md_process at least once due to cache attacks
* that observe whether md_process() was called of not */
for( j = 0; j < extra_run + 1; j++ )
mbedtls_md_process( &ssl->transform_in->md_ctx_dec, ssl->in_msg );
mbedtls_md_hmac_reset( &ssl->transform_in->md_ctx_dec );
/* Make sure we access all the memory that could contain the MAC,
* before we check it in the next code block. This makes the
* synchronisation requirements for just-in-time Prime+Probe
* attacks much tighter and hopefully impractical. */
ssl_read_memory( ssl->in_msg + min_len,
max_len - min_len + ssl->transform_in->maclen );
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_BUF( 4, "expected mac", mac_expect, ssl->transform_in->maclen );
MBEDTLS_SSL_DEBUG_BUF( 4, "message mac", ssl->in_msg + ssl->in_msglen,
ssl->transform_in->maclen );
#endif
if( mbedtls_ssl_safer_memcmp( ssl->in_msg + ssl->in_msglen, mac_expect,
ssl->transform_in->maclen ) != 0 )
{
#if defined(MBEDTLS_SSL_DEBUG_ALL)
MBEDTLS_SSL_DEBUG_MSG( 1, ( "message mac does not match" ) );
#endif
correct = 0;
}
auth_done++;
}
/*
* Finally check the correct flag
*/
if( correct == 0 )
return( MBEDTLS_ERR_SSL_INVALID_MAC );
#endif /* SSL_SOME_MODES_USE_MAC */
/* Make extra sure authentication was performed, exactly once */
if( auth_done != 1 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
if( ssl->in_msglen == 0 )
{
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3
&& ssl->in_msgtype != MBEDTLS_SSL_MSG_APPLICATION_DATA )
{
/* TLS v1.2 explicitly disallows zero-length messages which are not application data */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid zero-length message type: %d", ssl->in_msgtype ) );
return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
ssl->nb_zero++;
/*
* Three or more empty messages may be a DoS attack
* (excessive CPU consumption).
*/
if( ssl->nb_zero > 3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received four consecutive empty "
"messages, possible DoS attack" ) );
return( MBEDTLS_ERR_SSL_INVALID_MAC );
}
}
else
ssl->nb_zero = 0;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
; /* in_ctr read from peer, not maintained internally */
}
else
#endif
{
unsigned char i;
for( i = 8; i > ssl_ep_len( ssl ); i-- )
if( ++ssl->in_ctr[i - 1] != 0 )
break;
/* The loop goes to its end iff the counter is wrapping */
if( i == ssl_ep_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) );
return( MBEDTLS_ERR_SSL_COUNTER_WRAPPING );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) );
return( 0 );
}
#undef MAC_NONE
#undef MAC_PLAINTEXT
#undef MAC_CIPHERTEXT
#if defined(MBEDTLS_ZLIB_SUPPORT)
/*
* Compression/decompression functions
*/
static int ssl_compress_buf( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *msg_post = ssl->out_msg;
ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf;
size_t len_pre = ssl->out_msglen;
unsigned char *msg_pre = ssl->compress_buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> compress buf" ) );
if( len_pre == 0 )
return( 0 );
memcpy( msg_pre, ssl->out_msg, len_pre );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before compression: msglen = %d, ",
ssl->out_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "before compression: output payload",
ssl->out_msg, ssl->out_msglen );
ssl->transform_out->ctx_deflate.next_in = msg_pre;
ssl->transform_out->ctx_deflate.avail_in = len_pre;
ssl->transform_out->ctx_deflate.next_out = msg_post;
ssl->transform_out->ctx_deflate.avail_out = MBEDTLS_SSL_OUT_BUFFER_LEN - bytes_written;
ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH );
if( ret != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
ssl->out_msglen = MBEDTLS_SSL_OUT_BUFFER_LEN -
ssl->transform_out->ctx_deflate.avail_out - bytes_written;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ",
ssl->out_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "after compression: output payload",
ssl->out_msg, ssl->out_msglen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= compress buf" ) );
return( 0 );
}
static int ssl_decompress_buf( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *msg_post = ssl->in_msg;
ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf;
size_t len_pre = ssl->in_msglen;
unsigned char *msg_pre = ssl->compress_buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) );
if( len_pre == 0 )
return( 0 );
memcpy( msg_pre, ssl->in_msg, len_pre );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %d, ",
ssl->in_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "before decompression: input payload",
ssl->in_msg, ssl->in_msglen );
ssl->transform_in->ctx_inflate.next_in = msg_pre;
ssl->transform_in->ctx_inflate.avail_in = len_pre;
ssl->transform_in->ctx_inflate.next_out = msg_post;
ssl->transform_in->ctx_inflate.avail_out = MBEDTLS_SSL_IN_BUFFER_LEN -
header_bytes;
ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH );
if( ret != Z_OK )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) );
return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
}
ssl->in_msglen = MBEDTLS_SSL_IN_BUFFER_LEN -
ssl->transform_in->ctx_inflate.avail_out - header_bytes;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ",
ssl->in_msglen ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "after decompression: input payload",
ssl->in_msg, ssl->in_msglen );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) );
return( 0 );
}
#endif /* MBEDTLS_ZLIB_SUPPORT */
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
static int ssl_write_hello_request( mbedtls_ssl_context *ssl );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_resend_hello_request( mbedtls_ssl_context *ssl )
{
/* If renegotiation is not enforced, retransmit until we would reach max
* timeout if we were using the usual handshake doubling scheme */
if( ssl->conf->renego_max_records < 0 )
{
uint32_t ratio = ssl->conf->hs_timeout_max / ssl->conf->hs_timeout_min + 1;
unsigned char doublings = 1;
while( ratio != 0 )
{
++doublings;
ratio >>= 1;
}
if( ++ssl->renego_records_seen > doublings )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "no longer retransmitting hello request" ) );
return( 0 );
}
}
return( ssl_write_hello_request( ssl ) );
}
#endif
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
/*
* Fill the input message buffer by appending data to it.
* The amount of data already fetched is in ssl->in_left.
*
* If we return 0, is it guaranteed that (at least) nb_want bytes are
* available (from this read and/or a previous one). Otherwise, an error code
* is returned (possibly EOF or WANT_READ).
*
* With stream transport (TLS) on success ssl->in_left == nb_want, but
* with datagram transport (DTLS) on success ssl->in_left >= nb_want,
* since we always read a whole datagram at once.
*
* For DTLS, it is up to the caller to set ssl->next_record_offset when
* they're done reading a record.
*/
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want )
{
int ret;
size_t len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> fetch input" ) );
if( ssl->f_recv == NULL && ssl->f_recv_timeout == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
"or mbedtls_ssl_set_bio()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
if( nb_want > MBEDTLS_SSL_IN_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
uint32_t timeout;
/* Just to be sure */
if( ssl->f_set_timer == NULL || ssl->f_get_timer == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "You must use "
"mbedtls_ssl_set_timer_cb() for DTLS" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/*
* The point is, we need to always read a full datagram at once, so we
* sometimes read more then requested, and handle the additional data.
* It could be the rest of the current record (while fetching the
* header) and/or some other records in the same datagram.
*/
/*
* Move to the next record in the already read datagram if applicable
*/
if( ssl->next_record_offset != 0 )
{
if( ssl->in_left < ssl->next_record_offset )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->in_left -= ssl->next_record_offset;
if( ssl->in_left != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %d",
ssl->next_record_offset ) );
memmove( ssl->in_hdr,
ssl->in_hdr + ssl->next_record_offset,
ssl->in_left );
}
ssl->next_record_offset = 0;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
/*
* Done if we already have enough data.
*/
if( nb_want <= ssl->in_left)
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
return( 0 );
}
/*
* A record can't be split accross datagrams. If we need to read but
* are not at the beginning of a new record, the caller did something
* wrong.
*/
if( ssl->in_left != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Don't even try to read if time's out already.
* This avoids by-passing the timer when repeatedly receiving messages
* that will end up being dropped.
*/
if( ssl_check_timer( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timer has expired" ) );
ret = MBEDTLS_ERR_SSL_TIMEOUT;
}
else
{
len = MBEDTLS_SSL_IN_BUFFER_LEN - ( ssl->in_hdr - ssl->in_buf );
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
timeout = ssl->handshake->retransmit_timeout;
else
timeout = ssl->conf->read_timeout;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "f_recv_timeout: %u ms", timeout ) );
if( ssl->f_recv_timeout != NULL )
ret = ssl->f_recv_timeout( ssl->p_bio, ssl->in_hdr, len,
timeout );
else
ret = ssl->f_recv( ssl->p_bio, ssl->in_hdr, len );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
if( ret == 0 )
return( MBEDTLS_ERR_SSL_CONN_EOF );
}
if( ret == MBEDTLS_ERR_SSL_TIMEOUT )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "timeout" ) );
ssl_set_timer( ssl, 0 );
if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER )
{
if( ssl_double_retransmit_timeout( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "handshake timeout" ) );
return( MBEDTLS_ERR_SSL_TIMEOUT );
}
if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_resend", ret );
return( ret );
}
return( MBEDTLS_ERR_SSL_WANT_READ );
}
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_RENEGOTIATION)
else if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_PENDING )
{
if( ( ret = ssl_resend_hello_request( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_resend_hello_request", ret );
return( ret );
}
return( MBEDTLS_ERR_SSL_WANT_READ );
}
#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_RENEGOTIATION */
}
if( ret < 0 )
return( ret );
ssl->in_left = ret;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
while( ssl->in_left < nb_want )
{
len = nb_want - ssl->in_left;
if( ssl_check_timer( ssl ) != 0 )
ret = MBEDTLS_ERR_SSL_TIMEOUT;
else
{
if( ssl->f_recv_timeout != NULL )
{
ret = ssl->f_recv_timeout( ssl->p_bio,
ssl->in_hdr + ssl->in_left, len,
ssl->conf->read_timeout );
}
else
{
ret = ssl->f_recv( ssl->p_bio,
ssl->in_hdr + ssl->in_left, len );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d",
ssl->in_left, nb_want ) );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_recv(_timeout)", ret );
if( ret == 0 )
return( MBEDTLS_ERR_SSL_CONN_EOF );
if( ret < 0 )
return( ret );
if ( (size_t)ret > len || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "f_recv returned %d bytes but only %lu were requested",
ret, (unsigned long)len ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->in_left += ret;
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= fetch input" ) );
return( 0 );
}
/*
* Flush any data not yet written
*/
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *buf;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> flush output" ) );
if( ssl->f_send == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad usage of mbedtls_ssl_set_bio() "
"or mbedtls_ssl_set_bio()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/* Avoid incrementing counter if data is flushed */
if( ssl->out_left == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
return( 0 );
}
while( ssl->out_left > 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d",
mbedtls_ssl_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) );
buf = ssl->out_hdr - ssl->out_left;
ret = ssl->f_send( ssl->p_bio, buf, ssl->out_left );
MBEDTLS_SSL_DEBUG_RET( 2, "ssl->f_send", ret );
if( ret <= 0 )
return( ret );
if( (size_t)ret > ssl->out_left || ( INT_MAX > SIZE_MAX && ret > SIZE_MAX ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "f_send returned %d bytes but only %lu bytes were sent",
ret, (unsigned long)ssl->out_left ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ssl->out_left -= ret;
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ssl->out_hdr = ssl->out_buf;
}
else
#endif
{
ssl->out_hdr = ssl->out_buf + 8;
}
ssl_update_out_pointers( ssl, ssl->transform_out );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= flush output" ) );
return( 0 );
}
/*
* Functions to handle the DTLS retransmission state machine
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/*
* Append current handshake message to current outgoing flight
*/
static int ssl_flight_append( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_flight_item *msg;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> ssl_flight_append" ) );
MBEDTLS_SSL_DEBUG_BUF( 4, "message appended to flight",
ssl->out_msg, ssl->out_msglen );
/* Allocate space for current message */
if( ( msg = mbedtls_calloc( 1, sizeof( mbedtls_ssl_flight_item ) ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed",
sizeof( mbedtls_ssl_flight_item ) ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
if( ( msg->p = mbedtls_calloc( 1, ssl->out_msglen ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc %d bytes failed", ssl->out_msglen ) );
mbedtls_free( msg );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
/* Copy current handshake message with headers */
memcpy( msg->p, ssl->out_msg, ssl->out_msglen );
msg->len = ssl->out_msglen;
msg->type = ssl->out_msgtype;
msg->next = NULL;
/* Append to the current flight */
if( ssl->handshake->flight == NULL )
ssl->handshake->flight = msg;
else
{
mbedtls_ssl_flight_item *cur = ssl->handshake->flight;
while( cur->next != NULL )
cur = cur->next;
cur->next = msg;
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_flight_append" ) );
return( 0 );
}
/*
* Free the current flight of handshake messages
*/
static void ssl_flight_free( mbedtls_ssl_flight_item *flight )
{
mbedtls_ssl_flight_item *cur = flight;
mbedtls_ssl_flight_item *next;
while( cur != NULL )
{
next = cur->next;
mbedtls_free( cur->p );
mbedtls_free( cur );
cur = next;
}
}
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
static void ssl_dtls_replay_reset( mbedtls_ssl_context *ssl );
#endif
/*
* Swap transform_out and out_ctr with the alternative ones
*/
static void ssl_swap_epochs( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_transform *tmp_transform;
unsigned char tmp_out_ctr[8];
if( ssl->transform_out == ssl->handshake->alt_transform_out )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) );
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) );
/* Swap transforms */
tmp_transform = ssl->transform_out;
ssl->transform_out = ssl->handshake->alt_transform_out;
ssl->handshake->alt_transform_out = tmp_transform;
/* Swap epoch + sequence_number */
memcpy( tmp_out_ctr, ssl->cur_out_ctr, 8 );
memcpy( ssl->cur_out_ctr, ssl->handshake->alt_out_ctr, 8 );
memcpy( ssl->handshake->alt_out_ctr, tmp_out_ctr, 8 );
/* Adjust to the newly activated transform */
ssl_update_out_pointers( ssl, ssl->transform_out );
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_activate != NULL )
{
if( ( ret = mbedtls_ssl_hw_record_activate( ssl, MBEDTLS_SSL_CHANNEL_OUTBOUND ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_activate", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
}
#endif
}
/*
* Retransmit the current flight of messages.
*/
int mbedtls_ssl_resend( mbedtls_ssl_context *ssl )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_resend" ) );
ret = mbedtls_ssl_flight_transmit( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_resend" ) );
return( ret );
}
/*
* Transmit or retransmit the current flight of messages.
*
* Need to remember the current message in case flush_output returns
* WANT_WRITE, causing us to exit this function and come back later.
* This function must be called until state is no longer SENDING.
*/
int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl )
{
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_flight_transmit" ) );
if( ssl->handshake->retransmit_state != MBEDTLS_SSL_RETRANS_SENDING )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "initialise flight transmission" ) );
ssl->handshake->cur_msg = ssl->handshake->flight;
ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12;
ssl_swap_epochs( ssl );
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING;
}
while( ssl->handshake->cur_msg != NULL )
{
size_t max_frag_len;
const mbedtls_ssl_flight_item * const cur = ssl->handshake->cur_msg;
int const is_finished =
( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE &&
cur->p[0] == MBEDTLS_SSL_HS_FINISHED );
uint8_t const force_flush = ssl->disable_datagram_packing == 1 ?
SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH;
/* Swap epochs before sending Finished: we can't do it after
* sending ChangeCipherSpec, in case write returns WANT_READ.
* Must be done before copying, may change out_msg pointer */
if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) );
ssl_swap_epochs( ssl );
}
ret = ssl_get_remaining_payload_in_datagram( ssl );
if( ret < 0 )
return( ret );
max_frag_len = (size_t) ret;
/* CCS is copied as is, while HS messages may need fragmentation */
if( cur->type == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
if( max_frag_len == 0 )
{
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
continue;
}
memcpy( ssl->out_msg, cur->p, cur->len );
ssl->out_msglen = cur->len;
ssl->out_msgtype = cur->type;
/* Update position inside current message */
ssl->handshake->cur_msg_p += cur->len;
}
else
{
const unsigned char * const p = ssl->handshake->cur_msg_p;
const size_t hs_len = cur->len - 12;
const size_t frag_off = p - ( cur->p + 12 );
const size_t rem_len = hs_len - frag_off;
size_t cur_hs_frag_len, max_hs_frag_len;
if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) )
{
if( is_finished )
ssl_swap_epochs( ssl );
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
continue;
}
max_hs_frag_len = max_frag_len - 12;
cur_hs_frag_len = rem_len > max_hs_frag_len ?
max_hs_frag_len : rem_len;
if( frag_off == 0 && cur_hs_frag_len != hs_len )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "fragmenting handshake message (%u > %u)",
(unsigned) cur_hs_frag_len,
(unsigned) max_hs_frag_len ) );
}
/* Messages are stored with handshake headers as if not fragmented,
* copy beginning of headers then fill fragmentation fields.
* Handshake headers: type(1) len(3) seq(2) f_off(3) f_len(3) */
memcpy( ssl->out_msg, cur->p, 6 );
ssl->out_msg[6] = ( ( frag_off >> 16 ) & 0xff );
ssl->out_msg[7] = ( ( frag_off >> 8 ) & 0xff );
ssl->out_msg[8] = ( ( frag_off ) & 0xff );
ssl->out_msg[ 9] = ( ( cur_hs_frag_len >> 16 ) & 0xff );
ssl->out_msg[10] = ( ( cur_hs_frag_len >> 8 ) & 0xff );
ssl->out_msg[11] = ( ( cur_hs_frag_len ) & 0xff );
MBEDTLS_SSL_DEBUG_BUF( 3, "handshake header", ssl->out_msg, 12 );
/* Copy the handshake message content and set records fields */
memcpy( ssl->out_msg + 12, p, cur_hs_frag_len );
ssl->out_msglen = cur_hs_frag_len + 12;
ssl->out_msgtype = cur->type;
/* Update position inside current message */
ssl->handshake->cur_msg_p += cur_hs_frag_len;
}
/* If done with the current message move to the next one if any */
if( ssl->handshake->cur_msg_p >= cur->p + cur->len )
{
if( cur->next != NULL )
{
ssl->handshake->cur_msg = cur->next;
ssl->handshake->cur_msg_p = cur->next->p + 12;
}
else
{
ssl->handshake->cur_msg = NULL;
ssl->handshake->cur_msg_p = NULL;
}
}
/* Actually send the message out */
if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
return( ret );
}
}
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
/* Update state and set timer */
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER )
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
else
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_flight_transmit" ) );
return( 0 );
}
/*
* To be called when the last message of an incoming flight is received.
*/
void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl )
{
/* We won't need to resend that one any more */
ssl_flight_free( ssl->handshake->flight );
ssl->handshake->flight = NULL;
ssl->handshake->cur_msg = NULL;
/* The next incoming flight will start with this msg_seq */
ssl->handshake->in_flight_start_seq = ssl->handshake->in_msg_seq;
/* We don't want to remember CCS's across flight boundaries. */
ssl->handshake->buffering.seen_ccs = 0;
/* Clear future message buffering structure. */
ssl_buffering_free( ssl );
/* Cancel timer */
ssl_set_timer( ssl, 0 );
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
}
else
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_PREPARING;
}
/*
* To be called when the last message of an outgoing flight is send.
*/
void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl )
{
ssl_reset_retransmit_timeout( ssl );
ssl_set_timer( ssl, ssl->handshake->retransmit_timeout );
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] == MBEDTLS_SSL_HS_FINISHED )
{
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_FINISHED;
}
else
ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_WAITING;
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/*
* Handshake layer functions
*/
/*
* Write (DTLS: or queue) current handshake (including CCS) message.
*
* - fill in handshake headers
* - update handshake checksum
* - DTLS: save message for resending
* - then pass to the record layer
*
* DTLS: except for HelloRequest, messages are only queued, and will only be
* actually sent when calling flight_transmit() or resend().
*
* Inputs:
* - ssl->out_msglen: 4 + actual handshake message len
* (4 is the size of handshake headers for TLS)
* - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc)
* - ssl->out_msg + 4: the handshake message body
*
* Outputs, ie state before passing to flight_append() or write_record():
* - ssl->out_msglen: the length of the record contents
* (including handshake headers but excluding record headers)
* - ssl->out_msg: the record contents (handshake headers + content)
*/
int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
{
int ret;
const size_t hs_len = ssl->out_msglen - 4;
const unsigned char hs_type = ssl->out_msg[0];
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write handshake message" ) );
/*
* Sanity checks
*/
if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC )
{
/* In SSLv3, the client might send a NoCertificate alert. */
#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C)
if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT &&
ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) )
#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST &&
ssl->handshake == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
ssl->handshake != NULL &&
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#endif
/* Double-check that we did not exceed the bounds
* of the outgoing record buffer.
* This should never fail as the various message
* writing functions must obey the bounds of the
* outgoing record buffer, but better be safe.
*
* Note: We deliberately do not check for the MTU or MFL here.
*/
if( ssl->out_msglen > MBEDTLS_SSL_OUT_CONTENT_LEN )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Record too large: "
"size %u, maximum %u",
(unsigned) ssl->out_msglen,
(unsigned) MBEDTLS_SSL_OUT_CONTENT_LEN ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Fill handshake headers
*/
if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
{
ssl->out_msg[1] = (unsigned char)( hs_len >> 16 );
ssl->out_msg[2] = (unsigned char)( hs_len >> 8 );
ssl->out_msg[3] = (unsigned char)( hs_len );
/*
* DTLS has additional fields in the Handshake layer,
* between the length field and the actual payload:
* uint16 message_seq;
* uint24 fragment_offset;
* uint24 fragment_length;
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
/* Make room for the additional DTLS fields */
if( MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen < 8 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DTLS handshake message too large: "
"size %u, maximum %u",
(unsigned) ( hs_len ),
(unsigned) ( MBEDTLS_SSL_OUT_CONTENT_LEN - 12 ) ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
memmove( ssl->out_msg + 12, ssl->out_msg + 4, hs_len );
ssl->out_msglen += 8;
/* Write message_seq and update it, except for HelloRequest */
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
{
ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF;
ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF;
++( ssl->handshake->out_msg_seq );
}
else
{
ssl->out_msg[4] = 0;
ssl->out_msg[5] = 0;
}
/* Handshake hashes are computed without fragmentation,
* so set frag_offset = 0 and frag_len = hs_len for now */
memset( ssl->out_msg + 6, 0x00, 3 );
memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Update running hashes of handshake messages seen */
if( hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
ssl->handshake->update_checksum( ssl, ssl->out_msg, ssl->out_msglen );
}
/* Either send now, or just save to be sent (and resent) later */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) )
{
if( ( ret = ssl_flight_append( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_flight_append", ret );
return( ret );
}
}
else
#endif
{
if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
}
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write handshake message" ) );
return( 0 );
}
/*
* Record layer functions
*/
/*
* Write current record.
*
* Uses:
* - ssl->out_msgtype: type of the message (AppData, Handshake, Alert, CCS)
* - ssl->out_msglen: length of the record content (excl headers)
* - ssl->out_msg: record content
*/
int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush )
{
int ret, done = 0;
size_t len = ssl->out_msglen;
uint8_t flush = force_flush;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) );
#if defined(MBEDTLS_ZLIB_SUPPORT)
if( ssl->transform_out != NULL &&
ssl->session_out->compression == MBEDTLS_SSL_COMPRESS_DEFLATE )
{
if( ( ret = ssl_compress_buf( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compress_buf", ret );
return( ret );
}
len = ssl->out_msglen;
}
#endif /*MBEDTLS_ZLIB_SUPPORT */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
if( mbedtls_ssl_hw_record_write != NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_write()" ) );
ret = mbedtls_ssl_hw_record_write( ssl );
if( ret != 0 && ret != MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_hw_record_write", ret );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
if( ret == 0 )
done = 1;
}
#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
if( !done )
{
unsigned i;
size_t protected_record_size;
ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype;
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, ssl->out_hdr + 1 );
memcpy( ssl->out_ctr, ssl->cur_out_ctr, 8 );
ssl->out_len[0] = (unsigned char)( len >> 8 );
ssl->out_len[1] = (unsigned char)( len );
if( ssl->transform_out != NULL )
{
if( ( ret = ssl_encrypt_buf( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret );
return( ret );
}
len = ssl->out_msglen;
ssl->out_len[0] = (unsigned char)( len >> 8 );
ssl->out_len[1] = (unsigned char)( len );
}
protected_record_size = len + mbedtls_ssl_hdr_len( ssl );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/* In case of DTLS, double-check that we don't exceed
* the remaining space in the datagram. */
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
ret = ssl_get_remaining_space_in_datagram( ssl );
if( ret < 0 )
return( ret );
if( protected_record_size > (size_t) ret )
{
/* Should never happen */
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}